1. Field of the Invention
The present invention relates to controlling network bandwidth of a user node in a broadband network and the protection of protected content, and more particularly to controlling redistribution of protected content such as copyrighted digital music, video, and the like.
2. Description of the Related Art
Broadband networks typically utilize asymmetric bandwidth allocation, where a network link from a user node at a customer premises to a network access server, also referred to an upstream link, has a substantially lower allocated upstream bandwidth than the corresponding downstream link from the network access server to the user node. Broadband networks typically provision bandwidth asymmetrically between the network access server and the user node based on an assumption that the upstream link will typically require less bandwidth than the downstream link. In particular, the upstream link typically will utilize relatively small-sized requests, for example, sending text-based HTTP requests to a web server or e-mail requests to an e-mail server, or sending e-mail messages, having sizes on the order of 10-200 kilobytes. In contrast, the downstream link typically is utilized by the user node for downloading digital content (e.g., application software, encoded audio, and/or video) stored in substantially larger data files, for example 10 megabytes (Mbytes) and above, often exceeding 100 Mbytes. For example, commercial Asymmetric Digital Subscriber Line (ADSL) providers may offer downstream rates up to 8 megabits per second (Mbps), whereas the upstream rate would typically have a maximum rate of 640 kbps.
Hence, any data can be delivered in the downstream link up to the allocated capacity, measured for example in terms of bandwidth. Any data can also be sent from the user node to a destination via the broadband network based on the capacity of the upstream link. In addition, certain protocol enhancements have been proposed to improve the quality of service for broadband content (e.g., broadband video services) by increasing bandwidth and/or minimizing latency. For example, broadband networks deployed using Asynchronous Transfer Mode (ATM) cell streams can partition bandwidth into “virtual circuits” to provide guaranteed quality of service. Broadband networks deployed using Internet Protocol (IP)-based networks may utilize the Resource Reservation Protocol (RSVP), established by the Internet Engineering Task Force (IETF) Resource Reservation Setup Protocol Working Group as Request for Comments (RFC) 2205, for setting up resource reservations in the Internet. In addition various proposals have been submitted to the IETF in an effort to provide improved Quality of Service in terms of optimizing delivery of broadband content.
A primary concern among service providers deploying broadband networks and content providers offering online media content (e.g., streaming video, video on demand, music on demand, e-books, etc.) involves the unauthorized distribution of content. In particular, data transmitted over the Internet is relatively unrestricted in that any user having access via a user node can distribute any data to any other computer. Hence, users can share files using peer-to-peer resources without providing royalty payments to content owners; such peer-to-peer resources have resulted in substantial enforcement efforts by copyright holders, as illustrated by lawsuits filed against Napster, Inc., Redwood City, Calif. by copyright holders.
Hence, substantial tensions arise between service providers and commercial content providers or content rights holders. In particular, the service providers offer data access services for users that enable the users to download, and potentially redistribute content. The content providers or content rights holders, however, are especially concerned about loss of royalty revenue due to unauthorized redistribution of copyrighted or licensed content after a commercial transaction involving payment by a user for content (e.g., a multi media file, streaming video, etc.). Although the content provider may require the user purchasing the content to agree to refrain from copying or redistributing the content, typically in the form of a licensing agreement, the content provider typically has limited means of enforcing the licensing agreement in a convenient manner. Note, however, that in peer-to-peer distribution models some receivers can elect to become secondary providers, owing a license payment from each redistribution point or receiver to the copyright holder. Such an arrangement, however, still does not guarantee payment of the royalty.
One proposal for limiting redistribution of content involves encryption, for example Secure Sockets Layer (SSL) connections between servers and user devices, to prevent eavesdroppers from obtaining contention information or associated transaction information without the necessary encryption key. The content itself also may be encrypted in the form of an encrypted media file, requiring the user to possess a decryption key which may be provided separately; such an arrangement, however, limits the flexibility of the user to utilize the encrypted content, for example if the user prefers to transfer the encrypted media file to another device within an associated home network. In addition, encrypted files require the ability to find the appropriate small-sized key when the relatively large-sized multimedia content object is used. If the key is lost, the user also loses the ability to access the content until someone determines how to “crack” the encryption cipher.
The restrictions imposed by encrypted media files also may be overcome by using MPEG encoder devices, for example the Replay TV 4000 commercially available from SONICblue, Inc., Santa Clara, Calif. Such MPEG encoder devices can encode and store decrypted content that has been recovered in the form of an the analog video signal for display on a monitor. Hence, decrypted content can be re-encoded for storage and transfer to an unauthorized user via the upstream link.
Use of embedded markers within an analog signal to indicate evidence of ownership and limited permissions-to use, also known as watermarks, can be used to limit redistribution and trace transfers of protected content, assuming the necessary redistribution is in place to detect the markers. However, watermarks can be removed once their existence and form have been determined. Hence, once a watermark has been removed, the formerly protected content can be sent across the Internet without an audit trail that otherwise could be used to trace the protected content.